DE102007050304A1 - Method for controlling a fuel supply system of an internal combustion engine - Google Patents

Abstract

In a method for controlling a fuel supply system (10) of an internal combustion engine with at least one combustion chamber (26) into which fuel can be injected via a fuel injector (18), wherein the fuel injector (18) with filled fuel supply system for performing a normal start with predetermined injection parameters is, the predetermined injection parameters for accelerating a first start of the internal combustion engine at a venting of the fuel supply system (10) performed filling with fuel modified.

Description

State of the art

The The present invention relates to a method for controlling a Fuel supply system of an internal combustion engine with at least a combustion chamber into which fuel via a fuel injector can be injected, the fuel injector when filled Fuel supply system for performing a normal start is controlled with predetermined injection parameters.

In Fuel supply systems of internal combustion engines, the fuel is usually promoted with the help of an electric fuel pump. The electric fuel pump is with the help of the control unit the internal combustion engine driven or supplied with voltage. At the Starting the engine runs the fuel pump as long as the control unit detects that the start switch is pressed becomes. When the internal combustion engine has started, the pump remains turned on, the controller recognizes that the Internal combustion engine was not put into operation or that unauthorized Operating state, a safety circuit is activated, the pumping of fuel with the ignition switched on and stationary engine prevented. This will ensure that, for example, after an accident, the promotion of Fuel is stopped quickly.

Since it is necessary that when starting the engine equal to a sufficient fuel pressure is available, there are fuel supply systems in which a flow of the fuel pump takes place, the fuel pump is already supplied with voltage before the engine starts. Such a fuel supply system with flow is, for example, in the document EP 0 679 220 B1 described.

This known fuel supply system performs a flow the fuel pump, which additionally distinguished will, whether it is the expected start of the engine is a regular start or a start with fuel filling, So for example, a first start or a start after a longer parked internal combustion engine or after a Repair in the fuel supply system. If it is known is a refill, the duration of the forward the fuel pump compared to a usual start extended.

Problems of the prior art

By such extended lead times is especially at a Kraftstofferstbefüllung usually only partially Venting of the fuel supply system achieved, wherein a compressed in this existing air cushion. However, that will be here both low-pressure and high-pressure system is not sufficient filled with fuel, so that still a plurality of injections is necessary to the fuel supply system over the Vent combustion chambers. However, this leads at a relatively long start time of more than 25 s, in particular at the so-called "initial start" after fuel filling.

Disclosure of the invention

task The present invention is therefore a method and an apparatus to provide a reduction in the starting time, especially during Allow starting after fuel filling.

This Problem is solved by a method for controlling a Fuel supply system of an internal combustion engine with at least a combustion chamber into which fuel via a fuel injector can be injected. The fuel injector is filled Fuel supply system for performing a normal start controlled with given injection parameters. The default Injection parameters are used to accelerate a first start of the Brennkraftma machine performed at a venting of the fuel supply system Filling with fuel modified.

The Invention thus enables accelerated venting the fuel supply system at the first start of the internal combustion engine, so that the start time at the first start of the engine reduced can be.

According to the invention the predetermined injection parameters injection quantities fixed during normal start be injected from the fuel injector into the combustion chamber, wherein the injection quantities at the venting of the fuel supply system completed filling with fuel increased become.

Consequently may be the structure of a required for the first start of the internal combustion engine minimum fuel pressure to be accelerated, while in the fuel supply system existing air is faster displaced from this.

The predetermined injection parameters are preferably given with Correction factors applied to increase the injection quantities.

The Invention can thus be used by a modification already System settings are realized inexpensively.

According to the invention the fuel injected into the combustion chamber to the fuel injector supplied from a storage space, wherein the predetermined Correction factors are reduced if one in the memory space existing actual fuel pressure exceeds an associated pressure threshold. The predetermined correction factors can be used with neutral values be replaced when the present in the storage space actual fuel pressure exceeds the pressure threshold for a predetermined period of time, so that the fuel injector with the predetermined injection parameters is controlled.

Consequently can be an on-demand enlargement of the Injection done, which is always effected when a Bleed the fuel supply system required is, whereas in normal operation of the internal combustion engine at vented tem Fuel supply system, the predetermined injection parameters Find application.

The given injection parameters can at least at a start injection from the fuel injector into the combustion chamber Define injection quantities to be injected. The specified injection parameters can also at least at a restart from the fuel injector into the combustion chamber to be injected injection quantities establish. The given injection parameters can also at least those in a post-start / warm-up injection of the Fuel injector in the combustion chamber to be injected injection quantities establish.

The The invention can thus be used to modify the predetermined injection parameters as long as in the fuel supply system carried out injections engage until complete deaeration of the Fuel supply system is guaranteed.

The The aforementioned problem is also solved by a computer program to carry out a method of controlling a fuel supply system an internal combustion engine having at least one combustion chamber, in the over a fuel injector fuel can be injected. Of the Fuel injector is filled with fuel supply system for performing a normal start with predetermined injection parameters driven. The computer program modifies the given injection parameters to accelerate a first start of the internal combustion engine at a for bleeding the fuel supply system Filling with fuel.

The The aforementioned problem is also solved by an internal combustion engine with at least one combustion chamber into which a fuel injector Fuel can be injected. The fuel injector is with filled fuel supply system to carry out a normal start with predetermined injection parameters controllable. The predetermined injection parameters are used to accelerate a first start the internal combustion engine at a venting of the fuel supply system performed filling with fuel modifiable.

Brief description of the drawings

following becomes an embodiment of the present invention explained in more detail with reference to the accompanying drawings. Showing:

1 a schematic representation of a fuel supply system of an internal combustion engine;

2 a schematic representation of a method for controlling the fuel supply system of 1 ,

embodiment the invention

1 shows a schematic representation of a fuel supply system 10 with a single cylinder of an internal combustion engine and associated components. An example is an internal combustion engine with direct injection (gasoline engine with direct fuel injection BDE) with a fuel tank 11 on which an electric fuel pump (EKP) 12 , a fuel filter 13 and a low pressure regulator 14 are arranged. These form with an adjoining fuel line 15 a low pressure system.

The fuel line 15 leads from the fuel tank 11 to a high pressure pump 16 , To the high pressure pump 16 closes a storage space or rail 17 at. At the storage room 17 are fuel injectors 18 arranged, preferably directly combustion chambers 26 associated with the internal combustion engine. These components form a high-pressure system.

In internal combustion engines with direct injection is every combustion chamber 26 at least one fuel injector 18 assigned as in 2 shown, but it can also be several fuel injectors 18 for every combustion chamber 26 be provided.

The fuel is through the electric fuel pump 12 from the fuel tank 11 over the fuel filter 13 and the fuel line 15 to the high pressure pump 16 promoted.

The fuel filter 13 has the task to remove foreign particles from the fuel. With the help of the low pressure regulator 14 the fuel pressure in a low pressure region of the fuel Ver supply system to a predetermined value, which is usually in the order of about 4 to 5 bar regulated. The high pressure pump 16 , which is preferably driven directly by the internal combustion engine, compresses the fuel and conveys it into the storage space 17 , The fuel pressure reaches values of up to about 150 bar.

In 1 is an example of a single combustion chamber 26 an internal combustion engine with direct injection shown. In general, the internal combustion engine has a plurality of cylinders, each with a combustion chamber 26 on. At the combustion chamber 26 are at least one fuel injector 18 , at least one spark plug 24 , at least one inlet valve 27 and at least one exhaust valve 28 arranged. The combustion chamber is powered by a piston 29 , which can slide up and down in the cylinder, limited.

About the inlet valve 27 Fresh air is taken from an intake tract 36 in the combustion chamber 26 sucked. With the help of the fuel injector 18 the fuel is directly in the combustion chamber 26 the internal combustion engine sprayed. With the spark plug 24 the fuel is ignited. Due to the expansion of the ignited fuel, the piston becomes 29 driven. The movement of the piston 29 is via a connecting rod 37 on a crankshaft 35 transfer. At the crankshaft 35 is a segmented disc 34 arranged by a speed sensor 30 is scanned. The speed sensor 30 generates a signal indicating the rotational motion of the crankshaft 35 characterized.

The exhaust gases produced during combustion pass through the outlet valve 28 from the combustion chamber 26 to an exhaust pipe 33 in which a temperature sensor 31 and a lambda probe 32 are arranged. With the help of the temperature sensor 31 the temperature and with the help of lambda probe 32 the oxygen content of the exhaust gases detected.

A pressure sensor 21 and a pressure control valve 19 are at the storage room 17 connected. The pressure control valve 19 is input side with the memory space 17 connected. On the output side, a return line leads 20 to the fuel line 15 , Instead of the pressure control valve 19 may also be a quantity control valve in the fuel supply system 10 come into use.

With the help of the pressure sensor 21 becomes the actual value of the fuel pressure in the storage space 17 captured and a control unit 25 fed. Through the control unit 25 On the basis of the detected actual value of the fuel pressure, a drive signal is formed with which the pressure control valve is actuated. The fuel injectors 18 are controlled via not shown electrical power amplifiers, inside or outside of the control unit 25 can be arranged. Via control signal lines 22 are the different actuators and sensors with the controller 25 connected.

In the control unit 25 Various functions that serve to control the internal combustion engines are implemented. In modern control units, these functions are programmed on a computer and then in a memory of the control unit 25 stored. The stored in memory functions are activated in response to the requirements of the internal combustion engine. In this case, in particular stringent requirements for the real-time capability of the control unit 25 posed. In principle, a pure hardware realization of the control of the internal combustion engine is possible as an alternative to a software implementation.

In the intake tract 36 is a throttle 38 arranged, whose rotational position via a signal line 39 and an associated, not shown here, electrical actuator by the controller 25 is adjustable.

In a first mode, the homogeneous operation of the internal combustion engine, the throttle valve 38 partially opened or closed depending on the desired air mass to be supplied. The fuel is from the fuel injector 18 while passing through the piston 29 Induced intake into the combustion chamber 26 injected. By simultaneously sucked air, the injected fuel is swirled and thus in the combustion chamber 26 essentially uniformly / homogeneously distributed. Thereafter, the fuel air mixture during a compression phase, in which by the piston 29 the volume of the combustion chamber 26 is reduced, then compressed, usually just before reaching the top dead center of the piston 29 from the spark plug 24 to be ignited.

In a second mode, the stratified operation of the internal combustion engine, the throttle valve 38 wide open. The fuel is from the fuel injector 18 while passing through the piston 29 caused compaction phase in the combustion chamber 26 injected. Then as before with the help of the spark plug 24 the fuel ignites, leaving the piston 29 is driven in the now taking place working phase by the expansion of the ignited fuel. Another possible operating mode is the homogeneous lean operation, in which fuel as in homogeneous operation during the intake into the combustion chamber 26 is injected.

During the injection process, the pressure in the rail 17 and thus on the rail side of the fuel injector 18 larger than in the combustion chamber 26 , Only so can fuel in the combustion chamber 26 be injected.

at an original start or first start of the internal combustion engine, in the Usually carried out in the engine or vehicle plant, have low and high pressure system first through venting a fuel filling, to prevent damage to the internal combustion engine. This is also in a so-called "partially filled System ", that is, a system that is partially, but not fully vented. This can be done a fuel supply system one over a longer Period of unused internal combustion engine or after a repair in the fuel supply system.

The following is a method for controlling the fuel supply system 10 from 1 for its venting and filling with fuel according to an embodiment of the invention with reference to the 1 and 2 described in detail. This method can also be used in a diesel engine; opposite to the 1 shown gasoline engine then fall the spark plug 24 with associated components and the lambda probe 32 path.

2 shows a flowchart of a method 200. for controlling the fuel supply system 10 from 1 to accelerate a first start of the internal combustion engine at a filling carried out for venting the fuel supply system with fuel. Here, a detailed explanation of known in the prior art method steps is omitted.

According to a preferred embodiment of the invention, the method is implemented as a computer program that is controlled by a suitable control and regulating device (eg control device 25 ) is executable, which is already provided in the internal combustion engine. Thus, the invention with existing components of the internal combustion engine can be realized easily and inexpensively.

The procedure 200. begins in step S201, in which a start request is made and it is determined whether this is a normal start or a first start. A start request for a normal start is present when the fuel supply system 10 already filled and thus for commissioning the internal combustion engine no venting of the fuel supply system 10 is required. A start request for a first start is in the context of the present invention, when the fuel supply system 10 not filled or only partially filled. In this case, a full-bleed initial charge or refueling is required to partially deflate the fuel supply system 10 required.

If it is determined in step S201 that a normal start is to be performed, it is executed in step S202. Otherwise, the procedure continues 200. in step S203, to an inventive control of the fuel supply system 10 to perform its venting.

In step S203, first, the lead time of the electric fuel pump (EKP) 12 extended, z. B. to a duration between 10 s and 20 s and preferably to a duration of 15 s. In step S204, the injection parameters predetermined for the internal combustion engine are modified. According to the invention, these determine injection quantities that are produced by the fuel injector during normal start 18 in the combustion chamber 26 be injected. In this case, according to the invention, at least those in a start injection, a Nachstarteinspritzung and / or a post-start / warm-up injection from the fuel injector into the combustion chamber 26 be modified injection quantities to be injected.

When bleeding the fuel supply system 10 To be performed Be filling with fuel, these injection quantities are increased. For this purpose, according to an embodiment of the invention, the se are subjected to predetermined correction factors in step S204.

In step S205, it is determined whether one in the memory space 17 existing actual fuel pressure exceeds an associated pressure threshold. Thus, it can be determined whether in the fuel supply system 10 is increased by the lengthened in step S203 lead time and the injection quantities increased in step S204 required for starting the internal combustion engine minimum fuel pressure, so that ignition of the internal combustion engine is possible. Accordingly, the process waits in step S205 until this minimum fuel pressure is established, and then proceeds to step S206.

In step S206, the internal combustion engine is ignited, ie, into the combustion chamber 26 The fuel injected with the engine is with the spark plug 24 inflamed. In step S207, the predetermined correction factors are then reduced to prevent too much fuel from entering the combustion chamber 26 is injected.

In step S208, it is determined whether in the memory space 17 present actual fuel pressure has exceeded the pressure threshold for a predetermined period of time. This determination serves to determine whether the operation of the internal combustion engine after the ignition in step S206 was carried out for an applicable time period at high pressure level. If this is the case, this is an indication of a stable running of the internal combustion engine, so that the predetermined correction factors in step S210 with Neutralwer can be replaced to. a control of the fuel injector 10 to enable with the injection parameters specified for normal operation. Otherwise, the procedure continues 200. in step S209.

In step S209, it is determined whether in the memory space 17 generated fuel pressure has dropped below the associated pressure threshold. If this is the case, it is assumed that a pressure drop has occurred and the procedure 200. returns to step S204. Otherwise, the procedure returns 200. back to step S208.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - EP 0679220 B1 [0003]

Claims (10)

Method for controlling a fuel supply system ( 10 ) an internal combustion engine having at least one combustion chamber ( 26 ) into which a fuel injector ( 18 ) Fuel can be injected, the fuel injector ( 18 ) is controlled with predetermined injection parameters when the fuel supply system is filled to carry out a normal start, characterized in that the predetermined injection parameters for accelerating a first start of the internal combustion engine at a venting of the fuel supply system ( 10 ) are modified with fuel. A method according to claim 1, characterized in that the predetermined injection parameters set injection quantities, which during normal start of the fuel injector ( 18 ) in the combustion chamber ( 26 ) are injected, wherein the injection quantities at the venting of the fuel supply system ( 10 ) performed filling with fuel. Method according to claim 2, characterized in that that the predetermined injection parameters with predetermined correction factors be applied to increase the injection quantities. A method according to claim 3, wherein the into the combustion chamber ( 26 ) injected fuel to the fuel injector ( 18 ) from a memory space ( 17 ), characterized in that the predetermined correction factors are reduced when one in the memory space ( 17 ) present actual fuel pressure exceeds an associated pressure threshold. A method according to claim 4, characterized in that the predetermined correction factors are replaced with neutral values, if the in the memory space ( 17 ) present actual fuel pressure exceeds the pressure threshold for a given period of time, so that the fuel injector ( 18 ) is controlled with the given injection parameters. Method according to one of the preceding claims, characterized in that the predetermined injection parameters at least those at a start injection from the fuel injector ( 18 ) in the combustion chamber ( 26 ) specify injection quantities to be injected. Method according to one of the preceding claims, characterized in that the predetermined injection parameters at least those in a Nachstarteinspritzung from the fuel injector ( 18 ) in the combustion chamber ( 26 ) specify injection quantities to be injected. Method according to one of the preceding claims, characterized in that the predetermined injection parameters at least in a post-start / warm-up injection from the fuel injector ( 18 ) in the combustion chamber ( 26 ) specify injection quantities to be injected. Computer program for carrying out a method for controlling a fuel supply system ( 10 ) an internal combustion engine having at least one combustion chamber ( 26 ) into which a fuel injector ( 18 ) Fuel is injected. can, wherein the fuel injector ( 18 ) is controlled with predetermined injection parameters when the fuel supply system is filled to carry out a normal start, characterized in that the computer program sets the predetermined injection parameters for accelerating a first start of the internal combustion engine at a time for venting the fuel supply system ( 10 ) performed filling with fuel modified. Internal combustion engine with at least one combustion chamber ( 26 ) into which a fuel injector ( 18 ) Fuel can be injected, the fuel injector ( 18 ) with filled fuel supply system for performing a normal start with predetermined injection parameters can be controlled, characterized in that the predetermined injection parameters for accelerating a first start of the internal combustion engine in a for bleeding the fuel supply system ( 10 ) are fuel-modifiable filling.